This article describes a randomized clinical trial in young patients, comparing metal-on-metal cemented resurfacing hip replacement with cemented total hip replacement. The trial was stopped early, mainly because of a high incidence of failure of the cemented resurfacing acetabular component. The results reinforce the importance of clinical trials for evaluating the safety and efficacy of prosthesis designs before being used in a large cohort of patients. Although there may be advantages of resurfacing hip replacement, trials are also required to demonstrate it has a midterm success that reasonably approaches that of total hip replacement.